Texas became the second U.S. state to confirm a case of locally transmitted zika virus on Monday, when state health officials announced that a woman living in Brownsville was found infected with the virus.

State authorities believe that the woman hadn’t recently traveled to Mexico or any other province that have been affected Zika outbreaks. The statement also confirmed that mosquitoes that spread the devastating disease are present in the state, triggering concern that the virus can spread to more people.

Officials underlined the affected woman isn’t pregnant. It is a significant detail as zika infection during pregnancy often leads to serious brain defects in newborns.

Chris Van Deusen, a spokesperson for the Texas Department of State Health Services, added, “We certainly have been preparing for this since getting reports of the virus out of South America. This is something we have been planning for and have been expecting to see for some time. It was a matter of when, and not a matter of if.”

The first state to report locally transmitted cases of zika virus was Florida. In July, Florida authorities confirmed four cases in which mosquitoes had transmitted the virus.

As Zika virus disease is spread by mosquitoes, the best form of prevention is protection against mosquito bites. Most cases have no symptoms, but when present they often resemble those of dengue fever, such as fever, headache, red eyes, joint pain and rash.